The digital deal of the day over at Amazon today is Piranha (2010), which is available for rental for only $.99.

This deal is valid only for today, Thursday, March 31, 2011, until midnight PST. Once you activate the rental through Amazon’s Instant Video service, you’ll have access to the movie for 24 hours. If you’re interested in purchasing the digital version, the cost is $14.99.

Also, if you’d like to own a physical copy of Piranha (which was called Piranha 3D in theaters), the Blu-ray is available for $22.99 while the DVD is $18.99. And if you’re set up for 3D home viewing, there’s also a 3D Blu-ray for $26.99.